Topband: EIRP Measurement

Tracey Gardner tracey.gardner at
Wed Feb 22 10:57:23 PST 2012

> Further - and this has gotten beyond the 160 meter scope of this list -
> 630 meter propagation will be almost entirely groundwave as ionospheric
> conditions generally do not support skywave (a primary reason for the
> use of LF and low MF for NDB).  Since skywave is not supported, it
> makes sense to base EIRP calculations on groundwave and include all
> of the losses.
> 73,
>    ... Joe, W4TV
 Ionospheric conditions do support skywave for a good part of the day.
A couple of days ago I received the NDB "AL" on 443kHz from Almaty, in 
Kazakhstan over a distance of some 3500 miles from my location in the U.K.
This reception took place just before 1800GMT as darkness fell.
There is no way that this reception was due to ground wave.
I could list numerous NDBs that I receive on a regular basis, well outside 
their daytime ground wave range.
 73s Tracey G5VU 

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